October 18th, 2016

MAVEN Gives Unprecedented Ultraviolet View of Mars

New global images of Mars from the MAVEN mission show the ultraviolet glow from the Martian atmosphere in unprecedented detail, revealing dynamic, previously invisible behavior. They include the first images of “nightglow” that can be used to show how winds circulate at high altitudes. Additionally, dayside ultraviolet imagery from the spacecraft shows how ozone amounts change over the seasons and how afternoon clouds form over giant Martian volcanoes. The images were taken by the MAVEN Imaging UltraViolet Spectrograph (IUVS).

“MAVEN obtained hundreds of such images in recent months, giving some of the best high-resolution ultraviolet coverage of Mars ever obtained,” said Nick Schneider of the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder. Schneider is presenting these results Oct. 19 at the American Astronomical Society Division for Planetary Sciences meeting in Pasadena, California.

September 16th, 2016

Mars had liquid water a billion years longer than we even thought possible

Valleys much younger than well-known ancient valley networks on Mars are evident near the informally named “Heart Lake” on Mars. This map presents color-coded topographical information overlaid onto a photo mosaic. Lower elevations are indicated with white and purple; higher elevations, yellow.
Credits: NASA/JPL-Caltech/ASU

Lakes and snowmelt-fed streams on Mars formed much later than previously thought possible, according to new findings using data primarily from NASA’s Mars Reconnaissance Orbiter.

The recently discovered lakes and streams appeared roughly a billion years after a well-documented, earlier era of wet conditions on ancient Mars. These results provide insight into the climate history of the Red Planet and suggest the surface conditions at this later time may also have been suitable for microbial life.

“We discovered valleys that carried water into lake basins,” said Sharon Wilson of the Smithsonian Institution, Washington, and the University of Virginia, Charlottesville. “Several lake basins filled and overflowed, indicating there was a considerable amount of water on the landscape during this time.”

Wilson and colleagues found evidence of these features in Mars’ northern Arabia Terra region by analyzing images from the Context Camera and High Resolution Imaging Science Experiment camera on the Mars Reconnaissance Orbiter and additional data from NASA’s Mars Global Surveyor and the European Space Agency’s Mars Express.

September 13th, 2016

Mars Rover Views Spectacular Layered Rock Formations

This view from the Mast Camera (Mastcam) on NASA’s Curiosity Mars rover shows a hillside outcrop with layered rocks within the “Murray Buttes” region on lower Mount Sharp.

The layered geologic past of Mars is revealed in stunning detail in new color images returned by NASA’s Curiosity Mars rover, which is currently exploring the “Murray Buttes” region of lower Mount Sharp. The new images arguably rival photos taken in U.S. National Parks.

Curiosity took the images with its Mast Camera (Mastcam) on Sept. 8. The rover team plans to assemble several large, color mosaics from the multitude of images taken at this location in the near future.

“Curiosity’s science team has been just thrilled to go on this road trip through a bit of the American desert Southwest on Mars,” said Curiosity Project Scientist Ashwin Vasavada, of NASA’s Jet Propulsion Laboratory, Pasadena, California.

August 17th, 2016

Gullies on Mars: Wet or Dry (Ice)?

Martian gullies were in the spotlight recently thanks to a NASA press release stating they were “likely not formed by liquid water.” The release concerns the publication of a new paper by Nuñez et al. in Geophysical Research Letters, which looked at spectral data of gullies from the Mars Reconnaissance Orbiter (MRO) Compact Reconnaissance Imaging Spectrometer for Mars (CRISM).

In their study, Nuñez and his colleagues looked at over 100 gullied locations on Mars. They found no evidence of minerals that would be expected to form in the presence of water. Rather than water, they point to sublimation of seasonal carbon dioxide frost as the main culprit behind gully formation on Mars. Other people have proposed a similar model to explain present-day activity in gullies, which appears to happen during periods of active defrosting. But this process has been a topic of debate among the Mars gullies community, and was a big discussion point at the “Martian Gullies and Their Earth Analogues” workshop in London back in June. Can this dry process explain both the initial formation of gullies and gullies’ modern-day activity?

May 15th, 2016

The seasons on Mars: NASA’s Curiosity rover paints a picture

NASA’s Curiosity rover completed its second Martian year – 687 Earth days – on May 11, meaning that its instruments have now tasted the red planet’s tendencies for two full orbits of the sun.

This allows scientists to begin separating unique events from those that recur year by year, laying the foundation for an understanding of seasonal variations in a host of different characteristics.

The fresh insights come at a time when talk of a manned mission to Mars is edging away from the arena of science fiction and towards the realm of human endeavor.

March 24th, 2016

NASA gravity map offers closest ever look at Mars

By tracking the gravitational pull on spacecraft over Mars, NASA has created one of the most detailed maps yet of the Red Planet’s surface, and what lies beneath.

“Gravity maps allow us to see inside a planet, just as a doctor uses an X-ray to see inside a patient,” Antonio Genova of the Massachusetts Institute of Technology (MIT) said in a statement.
“The new gravity map will be helpful for future Mars exploration, because better knowledge of the planet’s gravity anomalies helps mission controllers insert spacecraft more precisely into orbit about Mars.”
As well as providing insight for future missions, the gravity map also offers explanations for developments in the planet’s past.

March 10th, 2016

Close comet flyby threw Mars’ magnetic field into chaos

The close encounter between comet Siding Spring and Mars flooded the planet with an invisible tide of charged particles from the comet’s coma. The dense inner coma reached the surface of the planet, or nearly so. The comet’s powerful magnetic field temporarily merged with, and overwhelmed, the planet’s weak field, as shown in this artist’s depiction. Illustration credits: NASA/Goddard.

Just weeks before the historic encounter of comet C/2013 A1 (Siding Spring) with Mars in October 2014, NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft entered orbit around the Red Planet. To protect sensitive equipment aboard MAVEN from possible harm, some instruments were turned off during the flyby; the same was done for other Mars orbiters. But a few instruments, including MAVEN’s magnetometer, remained on, conducting observations from a front-row seat during the comet’s remarkably close flyby.
The one-of-a-kind opportunity gave scientists an intimate view of the havoc that the comet’s passing wreaked on the magnetic environment, or magnetosphere, around Mars. The effect was temporary but profound.

“Comet Siding Spring plunged the magnetic field around Mars into chaos,” said Jared Espley, a MAVEN science team member at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We think the encounter blew away part of Mars’ upper atmosphere, much like a strong solar storm would.”

November 27th, 2015

The Amazingly Creepy Way Mars Will Kill One of Its Moons

It was a rough month for Phobos, as astronomers decreed—yet again—that Mars is ripping its lumpy moon apart. But apparently, Phobos’ loss is the Red Planet’s gain. After the satellite is torn to pieces, its fragments will fan out into a disk and 20 million years from now, Mars will become a ringed planet.

That’s the conclusion of a UC Berkeley-led study published this week in Nature Geoscience, which takes Phobos’ violent demise to an unexpectedly beautiful conclusion. But this little moon’s fate is more than just a cosmic curiosity. Rather, the researchers argue that Phobos could be a window into the origin of ring systems throughout the Solar System and beyond.

November 5th, 2015

NASA Mission Reveals Speed of Solar Wind Stripping Martian Atmosphere

NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission has identified the process that appears to have played a key role in the transition of the Martian climate from an early, warm and wet environment that might have supported surface life to the cold, arid planet Mars is today.

MAVEN data have enabled researchers to determine the rate at which the Martian atmosphere currently is losing gas to space via stripping by the solar wind. The findings reveal that the erosion of Mars’ atmosphere increases significantly during solar storms. The scientific results from the mission appear in the Nov. 5 issues of the journals Science and Geophysical Research Letters.

“Mars appears to have had a thick atmosphere warm enough to support liquid water which is a key ingredient and medium for life as we currently know it,” said John Grunsfeld, astronaut and associate administrator for the NASA Science Mission Directorate in Washington. “Understanding what happened to the Mars atmosphere will inform our knowledge of the dynamics and evolution of any planetary atmosphere. Learning what can cause changes to a planet’s environment from one that could host microbes at the surface to one that doesn’t is important to know, and is a key question that is being addressed in NASA’s journey to Mars.”

October 27th, 2015

SwRI scientists predict that rocky planets formed from ‘pebbles’

Using a new process in planetary formation modeling, where planets grow from tiny bodies called “pebbles,” Southwest Research Institute scientists can explain why Mars is so much smaller than Earth. This same process also explains the rapid formation of the gas giants Jupiter and Saturn, as reported earlier this year.

“This numerical simulation actually reproduces the structure of the inner solar system, with Earth, Venus, and a smaller Mars,” said Hal Levison, an Institute scientist at the SwRI Planetary Science Directorate. He is the first author of a new paper published in theProceedings of the National Academy of Sciences of the United States (PNAS) Early Edition.

The fact that Mars has only 10 percent of the mass of the Earth has been a long-standing puzzle for solar system theorists. In the standard model of planet formation, similarly sized objects accumulate and assimilate through a process called accretion; rocks incorporated other rocks, creating mountains; then mountains merged to form city-size objects, and so on. While typical accretion models generate good analogs to Earth and Venus, they predict that Mars should be of similar-size, or even larger than Earth. Additionally, these models also overestimate the overall mass of the asteroid belt.